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Home » Modeling » EMF » Issue with chunking in CDO
Issue with chunking in CDO [message #425234] Thu, 20 November 2008 13:21 Go to next message
Howard Bartfield is currently offline Howard BartfieldFriend
Messages: 5
Registered: July 2009
Junior Member
Hi

I've experienced an issue with chunking in CDO.

I think the problem may be due to the following:

[From org.eclipse.emf.cdo.server.internal.db.DBStoreChunkReader]

public void addRangedChunk(int fromIndex, int toIndex)
{
super.addRangedChunk(fromIndex, toIndex);
builder.append(" AND ");
builder.append(CDODBSchema.REFERENCES_IDX);
builder.append(" BETWEEN ");
builder.append(fromIndex);
builder.append(" AND ");
builder.append(toIndex);
}

I'm testing using CDO 1.0, on MySQL.

On MySQL, BETWEEN is inclusive of the upper bound - I think the code here
is assuming BETWEEN is NOT inclusive of the upper bound. (I believe
BETWEEN may behave differently on different databases.)

Including the upper bound causes an extra iteration of the loop which
reads the ResultSet in
org.eclipse.emf.cdo.server.internal.db.ReferenceMapping, in method
readChunks, and this results in an exception being thrown.

Regards
Howard.
Re: Issue with chunking in CDO [message #425235 is a reply to message #425234] Thu, 20 November 2008 13:29 Go to previous messageGo to next message
Simon Mc Duff is currently offline Simon Mc DuffFriend
Messages: 596
Registered: July 2009
Senior Member
Hi Howard,

You are totally right!!

The problem was already reported and fixed october 23, 2008. See below:
251864: [DB] ChunkReader not working with DBStore.
https://bugs.eclipse.org/bugs/show_bug.cgi?id=251864

It has been fix but only in 2.0.0.

Is it something you would like to have in 1.0.x ?

Simon


Howard Bartfield wrote:
> Hi
>
> I've experienced an issue with chunking in CDO.
>
> I think the problem may be due to the following:
>
> [From org.eclipse.emf.cdo.server.internal.db.DBStoreChunkReader]
>
> public void addRangedChunk(int fromIndex, int toIndex)
> {
> super.addRangedChunk(fromIndex, toIndex);
> builder.append(" AND ");
> builder.append(CDODBSchema.REFERENCES_IDX);
> builder.append(" BETWEEN ");
> builder.append(fromIndex);
> builder.append(" AND ");
> builder.append(toIndex);
> }
>
> I'm testing using CDO 1.0, on MySQL.
>
> On MySQL, BETWEEN is inclusive of the upper bound - I think the code
> here is assuming BETWEEN is NOT inclusive of the upper bound. (I believe
> BETWEEN may behave differently on different databases.)
>
> Including the upper bound causes an extra iteration of the loop which
> reads the ResultSet in
> org.eclipse.emf.cdo.server.internal.db.ReferenceMapping, in method
> readChunks, and this results in an exception being thrown.
>
> Regards
> Howard.
>
Re: Issue with chunking in CDO [message #425236 is a reply to message #425235] Thu, 20 November 2008 13:43 Go to previous messageGo to next message
Howard Bartfield is currently offline Howard BartfieldFriend
Messages: 5
Registered: July 2009
Junior Member
Ideally yes ... I'm very impressed with what I've seen of CDO so far, and
I'm looking forward to investigating it further. However, I think CDO 2.0
is going to come too late for my team, so for now I'm concentrating on 1.0.

Do you know if anyone has released any products using 1.0? If bugs are
found in 1.0, would someone be allowed to ship a fixed version, or is the
intention that bugs are 'officially' fixed by the EMF/CDO team and we then
take the fixes?

Thanks in advance,
Howard.
Re: Issue with chunking in CDO [message #425238 is a reply to message #425236] Thu, 20 November 2008 14:42 Go to previous messageGo to next message
Simon Mc Duff is currently offline Simon Mc DuffFriend
Messages: 596
Registered: July 2009
Senior Member
Howard Bartfield wrote:
> Ideally yes ... I'm very impressed with what I've seen of CDO so far,
> and I'm looking forward to investigating it further. However, I think
> CDO 2.0 is going to come too late for my team, so for now I'm
> concentrating on 1.0.
You could use 2.0 M3, but I understand that we could still change the
API and you will need to adjust!! :-)
You should know that the schema changed for 2.0. If you want to keep
your data some migration will be useful... we don't have any yet since
it could still change!:-)


>
> Do you know if anyone has released any products using 1.0?
I don't know all of them, I released a product october 2007 with CDO 0.8
:-) but the back-end was an homemade.

If bugs are
> found in 1.0, would someone be allowed to ship a fixed version, or is
> the intention that bugs are 'officially' fixed by the EMF/CDO team and
> we then take the fixes?
Usually we have maintenance release.
http://www.eclipse.org/modeling/emf/downloads/index.php?proj ect=cdo&showAll=0&showMax=5

We are now at 1.0.3... and We will probably have a 1.0.4 to fix your
issue. :-)

>
> Thanks in advance,
> Howard.
>

I created a bugzilla if you want to follow it!

https://bugs.eclipse.org/bugs/show_bug.cgi?id=255976
Re: Issue with chunking in CDO [message #425266 is a reply to message #425236] Fri, 21 November 2008 11:33 Go to previous message
Eike Stepper is currently offline Eike StepperFriend
Messages: 6483
Registered: July 2009
Senior Member
Howard,

I'm glad to hear that you're happy with CDO. Regarding
problems/fixes/releases, since CDO is EPL you can do with it whatever
you want except claiming you made it ;-) But you're right, normally we
expect users to only report problems (ideally, but not necessarily, with
a patch attached to fix the problem). Bugs are fixed by us in HEAD and
sometimes in the maintenance stream. Some time later we publish builds
of both streams.

Cheers
/Eike

----
http://thegordian.blogspot.com



Howard Bartfield schrieb:
> Ideally yes ... I'm very impressed with what I've seen of CDO so far,
> and I'm looking forward to investigating it further. However, I think
> CDO 2.0 is going to come too late for my team, so for now I'm
> concentrating on 1.0.
>
> Do you know if anyone has released any products using 1.0? If bugs are
> found in 1.0, would someone be allowed to ship a fixed version, or is
> the intention that bugs are 'officially' fixed by the EMF/CDO team and
> we then take the fixes?
>
> Thanks in advance,
> Howard.
>


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